Method of electric welding



June 19, 1928. 1,674,109

B. GROB METHOD OF ELECTRIC WELDING Filed May 1927 Emu/9M A7555 ATTORNEY.

Patented :hme 19,

3mm anon, or wear Anus, wrsconsm.

m!) 0] ELECTRIC WELDING. 8

Application fled Kay 8,

w This invention relates'to the art of electric weldin and particularly to the butt welding of heavy plates, heavy pipe sections and the like. V a Arc welding processes are now quite generally applied to the joining of heavy work of this character due largely to the hitherto in-- surmountab'le difiiculties involved 'in' attempting to efi'ect the pressures required for 1'0 the production of a sound joint by resistancewelding methods heretofore practiced. The arc welding process is not entirely satisfactory however on account of the excessive temperatures involved which cause a breaking down of the metal structure and a consequent impairment of the completed joint.

Nevertheless the arc welding process is still usedpractically exclusively for joining the abutting edges of heavy plates and heavy pipe seams in spite of numerous efiorts heretofore made to overcome the difliculties incident to the carryin out of resistance welding processes hereto ore known.

One objectof the present invention is the provision of an improved method of resistance welding which may be readily and satisfactorily applied to the butt welding of heavy plates, heavy pipe sections and heavy pipe seams. k

Other objects and advantages will appear from the following description of an application of my improved methodto the electric welding of .the longitudinal seams of heavy pipe sections. The .specific method described however should be considered as anexemplification of thepresent invention the scope of which is determined by the appended claims and the state of the prior art.

In the drawings:

For purposes of illustration and explana- 'Figure 1 is apdiagrammatic view in end 1927. Serial No. 189,240.

tion In improved method will be described as app led to the welding of a longitudinal scam in aheavy applicable with 1ke advantage to the butt welding of peripheral seams in 'oining heavy pipe sections and in butt weldmg the edges of hea plates which may be flat or otherwise. 11 carrying out my method I firmly clamp ihe work in position with the edges slightly spaced and in substantial parallel- 1pipe section, although it is 1sm. The work shown in the drawlngs is a heavy p1pe section 10, approximately eight feet in diameter and twenty four feet long with a wall thicknessof approximately four inches. The pipe is shown supported in three carriages 11, each mounted on wheels 12, and each embracing the pipe section at spaced points thereon. The pipe rests upon an appropriate lower bearing 13 in each carriage, which bearing cooperates with appropriate clamp screws 14 to firmly hold the pipe in position with the edges 15 thereof in proper spaced relation. Ametal fillet 16 is inserted, between the opposed edges 15 andextended the full length thereof. Thefillet,

.which may assumevanous forms, is of such width as to fit snugly between the edges 15 and, preferably of a depth somewhat greater than the thickness of the walls so as to project upwardly and downwardly beyond the surfaces thereof.

15 to provide a good forging temperature.

while the heated portion 'of the fillet is simultaneously subjected to a squeezing pressure to cause the same to spread laterally against the opposed edges 15 to thereby produce a good welding pressure between it and the edges. This combined heating and squeezing action is applied progressively at. successive localized points throughout the length of the seam thereby effecting an intimate union of the fillet with the edges of the work throughout.

. In order to obtain a substantially uniform heating of the fillet 16 and edges 15 I pass an electric current from edge to edge. of

the work through the fillet. In the apparatus shown use is made of two pairs of electrodes 17-17 and 18-18, -each pair e of electricity along diagonal intersecting paths from both edges through the 'fillct 16. Thus, as indicated in Figure 1, elec trodes 17 and 18 are applied tothe external surface of the pipe 10 adjacent opposite sides of the fillet 16 and electrodes 17 and 18 are applied to the internal surface of the pipe adjacent opposite sides of the fillet sothat current is caused to flow through the fillet between electrodes 17-17 and through the fillet between electrodes 18'-18'.

e squeezing pressureis preferably applied to the fillet in a dircctiontransversely of the current by any appropriate means such as a hydraulically operated ram 22 supplied with operating fluid from an appropriate pressure source through a hose 23 or the like. The ram shown is carried by a jaw 24 and reacts against an anvil 25 mounted upon a second jaw 26. The two' jaws are rigidly connected and supported to rock as a unit upon a pivot 27 carried by an a propriate upright28. During the process o welding the pipe 10 is moved-lengthwise with respect to the electrodes and 'ram, and thegram 1s intermittently operated to squeeze the fillet at successive localized points along the length thereof, as the fillet 16 and" edges 15 of the pipe are heated by the flow of current through the electrodes. 7 w

The fillet 16 shown in Figures 1 and 2 of rectangular cross section and ith'e edges.-

15 of the pipe are substantially flat and in full contactwith the sides of the fillets Othersliapes however may be employed. In

Figure 3, for instance, the fillet 16 is'in the form of a round rod and. the opposed edges 15 of -the work-are of concave form so as to make full contact with the 'sides of the fillet. Another form of fillet'16" 'is shown Figure 4 In this instance the fillet 16", is shaped to fprovide substantially narrow longitudinal aces 29 for contact with the opposed'edges 15" of the .work and tr nsversely tapered in both'directions from t ese' intermediate faces. The use ofthis form of fillet insures a good initial contract hetween" it and the edges- 15" the area of con,- tact increasing as the fillet is deformed under the squeezing pressure and rise in'temp'eramm 7 r m What I claim as new and 'desireto scour by Letters Patent is 2- f z 1. The improved method of electric welding which consists in firmlyparts to be welded in closely spaced relation, 7 a. metal fillet between and incon- -tact therew th, applying heat 10 said ,fillet and parts 8t Sll008SS1V6 localized points by an electric current therethrough and applying a. squeezing-p to the succeeedges during the (p to t e other of sai parts to heat thesame,

sively heated portions of said fillet in a di rection transverse to the current to spread the same and thereby effect a welding pres; sure between it and said parts.

2. The improved method of electric weld- ,ing which consists in securing the parts to bewelded in closely spaced relation, insertp ing a metal fillet between and in contact therewith, passing an electric current throu h said fillet from one of said parts to' 7 the ot er to heat the fillet and parts at -suc cessive localized points, and simultaneously squeezing the successively heated portions of said fillet to spread thesame ,into welding contact with said parts. 4 $0 3. The im roved method of electric welding heavy p ates'and the like which consists in firmly securing the plates in osition with their edges opposed and slight y spaced, -,in-\ serting a metal fillet between and m contact with the opposed edges so as to'project be yond the same, heating said edges and fillet at successive localized points by passing an electric current therethrough, and applying pressure to the opposite exposed sides of sai fillet transverselyof the current flow at the successively heated portions thereof to spread the same mto welding eontacts'with said edges. f y

4. The improved method of electric welding which consists in firmly securing the parts to be welded in position with their respective edges opposed and in spaced relation, inserting a metal fillet between said edges and in contact therewith within a portion onl of the depth thereof, heating s aid fillet an edges at successive localized points by passing an electric burrent therethroughfrom one of said parts to the other, and simultaneousl spreading the successively heated portlons of said fillet into welding contact with said edges. 1

5. An electric welding apparatus comprising clampingv means for oldingthe parts-i tobe wel ed in definite spaced relation, diagonally disposed pairs of electrodes f contact with said parts, separate circuits for the electrodes 0 each pair, and means for applying asqueezing pressure to a metal fillet interposed between said edges to spread the same into wel contact with said i the passage of ,electricity'- therethroughj 6. The improved method ing which consists in firmly securing the parts to be welded in closely spaced relation, inserting a metal fillet between and in cona electric weldtact'therewith, passing an electric current i fro one of said arts through said fillet and apply g Pressure to said filletin a direction transversely ofv thecurrent to spread said fillet and thereby efiectfipa' welding pressure between it and parts.

7. An electric weldini apparatus com risa direction transversel of the current to ing means for holding t e parts to be we ded spreadsaid fillet and t er'eby effect a weldin definite spaced relation with a fillet 'there- .ing pressurebetween it and said parts. 10 between, means for passing a current of elec- In witness whereof, I hereunto subscribe I 5 tricity from one of said parts through the my name this 3rd day of May, 1927.

v fillet to said other part, and means for a. p plying a squeezing pressure to said fillet'm BENJAMIN GROB. 

